Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each. Their size ranges from 2-3 to about 20 nm. What is special about this size regime that placed NCs among the hottest research topics of the last decades? The quantum mechanical coupling * To whom correspondence should be addressed. E-mail: dvtalapin@uchicago.edu. † The University of Chicago. ‡ Argonne National Lab. Chem. Rev. 2010, 110, 389–458 389

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Prospects of Colloidal Nanocrystals for Electronic and Optoelectronic Applications

-phenylenevinylene)s L4. Fluorene-Based Conjugated Polymers L4.1. Fluorene-Based Copolymers ContainingElectron-Rich MoietiesM4.2. Fluorene-Based Copolymers ContainingElectron-Deﬁcient MoietiesN4.3. Fluorene-Based Copolymers ContainingPhosphorescent ComplexesQ5. Carbazole-Based Conjugated Polymers R5.1. Poly(2,7-carbazole)-Based Polymers R5.2. Indolo[3,2-

https://ir.nctu.edu.tw:443/bitstream/11536/6508/1/000271856900020.pdf

Synthesis of Conjugated Polymers for Organic Solar Cell Applications

Aggregation-induced emission: phenomenon, mechanism and applications.

We review the present state of polymer nanocomposites research in which the fillers are single-wall or multiwall carbon nanotubes. By way of background we provide a brief synopsis about carbon nanotube materials and their suspensions. We summarize and critique various nanotube/polymer composite fabrication methods including solution mixing, melt mixing, and in situ polymerization with a particular emphasis on evaluating the dispersion state of the nanotubes. We discuss mechanical, electrical, rheological, thermal, and flammability properties separately and how these physical properties depend on the size, aspect ratio, loading, dispersion state, and alignment of nanotubes within polymer nanocomposites. Finally, we summarize the current challenges to and opportunities for efficiently translating the extraordinary properties of carbon nanotubes to polymer matrices in hopes of facilitating progress in this emerging area.

Polymer Nanocomposites Containing Carbon Nanotubes

Solution-processed bulk-heterojunction solar cells have gained serious attention during the last few years and are becoming established as one of the future photovoltaic technologies for low-cost power production. This article reviews the highlights of the last few years, and summarizes today's state-of-the-art performance. An outlook is given on relevant future materials and technologies that have the potential to guide this young photovoltaic technology towards the magic 10% regime. A cost model supplements the technical discussions, with practical aspects any photovoltaic technology needs to fulfil, and answers to the question as to whether low module costs can compensate lower lifetimes and performances.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.200801283

Polymer‐Fullerene Bulk‐Heterojunction Solar Cells

Alkylsabstituted polyfluorenes have emerged as a very attractive class of conju gated polymers, especially for display applications, owing to their pure blue and efficient electroluminescence coupled with a high charge-carrier mobility and good processability. The availability of specific and highly regroselective coupling reactions provides a rich variety of taifored polyfluorene-type paly mers and copolymers. The focus of this review, therefore, is on reliable structure-property relationships regarding (i) the interplay of substitution pattern, solid state morphology, and optical/electronic properties, and (ii) the key role of degradation-induced keto defect sites in fluorerse-type polymers, and strategies for obtaining defect-free polyfluorenes.

Semiconducting Polyfluorenes—Towards Reliable Structure–Property Relationships

The Effect of Keto Defect Sites on the Emission Properties of Polyfluorene-Type Materials

A polyfluorene 12 has been prepared in which bulky polyphenylene dendrimer substituents suppress formation of long wavelength emitting aggregates, thus giving a polymer with pure blue emission. Absorption- and emission spectra and molecular modeling confirm that the bulky dendrimer side chains do not cause extra torsion between the fluorene units. New polyfluorenes with 9,9-diaryl substituents have been prepared to determine the minimum size of substituent necessary for aggregation suppression. An LED using 12 has been demonstrated to produce blue emission with onset voltages below 4 V.

Polyfluorenes with Polyphenylene Dendron Side Chains: Toward Non-Aggregating, Light-Emitting Polymers

The field of organic electronics has seen tremendous progress over the last years and all-solution-based processes are believed to be one of the key routes to ultra low-cost roll-to-roll device and circuit fabrication. In this regard a variety of functional materials has been successfully designed for inkjet printing. While orthogonal-solvent approaches have frequently been used to tackle the solubility issue in multilayer solution processing, the focus of this work lies on printed metal electrodes for organic field-effect transistors (OFET) and their curing concepts. Two metallic inkjet-printable materials are studied: i) a silver-copper nanoparticle based dispersion and ii) a soluble organic silver-precursor. Photoelectron spectroscopy reveals largely metallic properties of the cured materials, which are compared with respect to OFET performance and process-related issues. Contact resistance of the prepared metal electrodes is significantly larger than that of evaporated top-contact gold electrodes. As direct patterning via inkjet printing limits the reliably achievable channel length to values well above 10 μm, the influence of contact resistance is rather small, however, and overall device performance is comparable.

Direct ink-jet printing of Ag-Cu nanoparticle and Ag-precursor based electrodes for OFET applications

An alternative method for producing efficient white light-emitting polymer diodes based on a blend of two polymers is reported. The white light emission is composed of a broad blue emission of laddertype (polyparaphenylene) (m-LPPP) and a red-orange emission of a new polymer, poly(perylene-co-diethynylbenzene) (PPDB). The red-orange electroluminescence emission is promoted by an excitation energy and charge transfer from m-LPPP to the PPDB. A concentration of 0.05% PPDB in the polymer blend is required in order to obtain white light emission. By inserting an insulating material in the blend, so that a maximum external quantum efficiency of 1.2% is obtained.

Emil List

Papers

Semiconducting Polyfluorenes—Towards Reliable Structure–Property Relationships

The Effect of Keto Defect Sites on the Emission Properties of Polyfluorene-Type Materials

Polyfluorenes with Polyphenylene Dendron Side Chains: Toward Non-Aggregating, Light-Emitting Polymers

Direct ink-jet printing of Ag-Cu nanoparticle and Ag-precursor based electrodes for OFET applications

Efficient white light-emitting diodes realized with new processable blends of conjugated polymers